Beverages and other comestibles are often processed and packaged on mechanized conveyor systems which are lubricated to reduce friction between the packaging and the load bearing surface of the conveyor. The lubricants commonly used on the load bearing surfaces of these conveyor systems, such as those used in the food processing, beverage and the brewery industries, typically contain fatty acid soaps as the active lubricating ingredient because of the superior lubricity provided by fatty acid soaps.
In addition to lubricants, conveyor systems used in the processing and packaging of comestibles are also commonly treated with an antimicrobial compound, particularly the moving portions of the conveyor system likely to carry a residue of a food substance, such as the load bearing surface, in order to reduce the population of microorganisms, such as bacteria, yeast and mold, which tend to grow on the system and produce slime. Unfortunately, those antimicrobial compounds found to be particularly effective for controlling microbiological populations on a conveyor system are difficult to combine with fatty acid soaps because many of these antimicrobial compounds are deactivated by the anionic fatty acids. For example, cationic quaternary ammonium compounds, which are widely recognized for their antimicrobial activity, are not generally employed as an antimicrobial compound on conveyor systems because they tend to be deactivated by the anionic fatty acid soaps used as the lubricant on such systems. Furthermore, combinations of a quaternary ammonium compound and a fatty acid soap are not typically employed because quaternary ammonium salts and fatty acids are known to be generally physically incompatible. However, because of their effectiveness as an antimicrobial compound, quaternary ammonium salts have been employed in lubricating compositions which are fatty acid free.
Davis et al., U.S. Pat. No. 4,289,636, disclose an aqueous lubricant useful in metal cutting fluids for assisting in the care and cleaning of ferrous and cupreous metal surfaces, which comprises a water soluble amide derived from the reaction of a primary alkylamine or a secondary alkylamine with a member selected from the group of succinic, tetrahydrophthaleic or tetrahydrofuran tetracarboxylic acids. Davis et al. further disclose that the composition may also include a germicidal compound such as a quaternary compound including a C.sub.12-16 alkyl group.
Jansen, U.S. Pat. No. 4,839,067 discloses a process for the maintenance of chain-type bottle conveyor belts which includes treating the conveyor belt with a lubricant composition containing a lubricating amount of a C.sub.12-18 primary fatty acid amine with periodic treatment of the conveyor belt with an antimicrobial composition, such as an organic acid. However, such fatty acid free lubricant compositions have generally proven to be less effective for lubricating load bearing surface of a conveyor system as those which include a fatty acid.
While generally effective for controlling microbe populations, such fatty acid free lubricant compositions have generally proven to be less effective for lubricating the load bearing surface of a conveyor system than those which include a fatty acid.
Accordingly, while various attempts have been made to produce a microbiologically effective conveyor lubricating composition which provides both effective lubricity and effective microbiological action, such compositions have not generally been effective for providing both properties and a substantial need still exists for a conveyor lubricant which provides a combination of superior lubricity and superior antimicrobial activity.